A Statistical Treatment of Cross-Polarization Modulation in DWDM Systems

Abstract

Abstract-Starting from a model of random nonlinear polarization rotations for the effect of cross-polarization modulation in DWDM systems, we derive the mean distribution of the time-dependent polarization states at an arbitrary location within an optical link. We show that this distribution is fully parameterized by the degree of polarization of the particular wavelength channel, and we derive expressions to approximate this parameter for general optical links consisting of multiple optically amplified and dispersion-compensated spans, as well as related power thresholds. From the analytical expressions we derive a method to significantly reduce the detrimental effects.Index Terms-Communication system nonlinearities, optical fiber communication, optical fiber polarization, optical fiber theory, optical Kerr effect.

Nonlinear signal–noise interactions in dispersion-managed links with various modulation formats

“…9(bottom-left) that, while in the single-channel case NLPN is the dominant impairment up to 60 Gbaud, in the WDM case with K ¼ 3 the impact of NSNI seems rather weak, with only 0.5 dB of NLT decrease with respect to noise loading in the range 20 < R < 60 Gbaud. This is attributed to the dominant role of another WDM nonlinearity, namely cross-polarization modulation (XPolM), whose basic mechanisms can be explained by some existing analytical models developed for OOK [42][43][44] and have recently been quantified in terms of depolarization induced on a probe channel in a large WDM multiplex [45]. Recent observations have pointed out that correct reproduction of XPolM effects requires more WDM channels than those needed for XPM reproduction [46,45].…”

“…This is attributed to the dominant role of another WDM nonlinearity, namely cross-polarization modulation (XPolM), whose basic mechanisms can be explained by some existing analytical models developed for OOK [42][43][44] and have recently been quantified in terms of depolarization induced on a probe channel in a large WDM multiplex [45]. Recent observations have pointed out that correct reproduction of XPolM effects requires more WDM channels than those needed for XPM reproduction [46,45]. Hence our NLT results obtained with the XPM-based scaling (10) of the number of WDM channels may be optimistic in this respect.…”

Polarization modulation instability in a Manakov fiber system

“…In particular, when considering the two coupled orthogonally polarized components of the optical field, the Manakov system admits trivial two-component stable solutions formed by two incoherent bright (self-focusing case) or dark (self-defocusing case) solitons. More generally, the Manakov system has attracted enormous attention as it is considered to be a promising model for the description of interactions between wavelengthdivision-multiplexed (WDM) channels of long optical fiber transmission systems [9], polarization-division-multiplexed systems (PDM) [10,11], or even space-division-multiplexed (SDM) systems using multimode or multicore fibers [12].…”

Investigation of nonlinear effects in few-mode fibers

“…In Fig. 1, the polarization of a co-propagating low-power CW signal can be rotated from vertical to horizontal and vice versa with a high-power CW channel linear polarized at 45 • , which is known as crosspolarization modulation (XPolM) in SMF [27]; meanwhile, the sum or subtraction frequency is generated as a different frequency from the pump light.…”